Police are investigating the fatal shooting early this morning of a man thought to be in his 20s near the Ministry of Sound nightclub in south London.

Another man, aged 29, also suffered gunshot wounds. He is in a stable condition in hospital.

The incident was the second shooting near a nightclub in the capital over the weekend. A gunman opened fire outside The Hill in Muswell Hill, north London, on Saturday morning, wounding three people. A 27-year-old woman was shot in the hand, a 23-year-old man shot in the chest, and a 28-year-old man shot in the neck.

A number of shootings have taken place near the Ministry of Sound nightclub in recent years. The club, owned by James Palumbo, celebrates its 18th anniversary next month.

The club has a cult following among clubbers worldwide after it was established at an unused bus depot on Gaunt Street, near Elephant & Castle, with the grungy look favoured by nightclubs in the early 1990s.

During the last few years the club has sought to move upmarket, hiring itself for corporate functions, but its reputation has been dogged by repeated violence in its vicinity.

Last month police were called after reports of a disturbance that left a 19-year-old man with severe head injuries. Seven men and one woman were arrested.

The latest violence comes despite attempts by police to curb gun crime and violence at clubs.

These include the controversial use of Form 696, which asks clubs to provide the name, address and contact telephone numbers for artists and promoters.

It also asked for details of which ethnic group was likely to attend the planned event.

That requirement was dropped last year after it received widespread criticism, but the form still asks promoters to say what style of music is to be played and gives "bashment, R&B, garage" as examples – genres popular with black and Asian people.

In a letter, musicians and figures from the entertainment industry have called on the government's equalities watchdog to intervene on the grounds that the form is racist.

Sunny Hundal, a journalist and organiser of the appeal to the Equality and Human Rights Commission, said that although the form was "voluntary", many events had applications for licences turned down after refusals to fill it in.

The letter, which has more than 50 signatories, states: "We are deeply concerned that Form 696 has the potential to be misused by the police to discriminate against ethnic minorities.

"There is now a danger that police across the country will adopt this measure and further entrench this illiberal and potentially racist practice."

Police say the use of the form has helped to reduce violence at certain music events.